THE french fry was "almost sacrosanct for me,"
Ray Kroc, one of the founders of McDonald's, wrote in his autobiography,
"its preparation a ritual to be followed religiously." During
the chain's early years french fries were made from scratch every day.
Russet Burbank potatoes were peeled, cut into shoestrings, and fried in
McDonald's kitchens. As the chain expanded nationwide, in the mid-1960s,
it sought to cut labor costs, reduce the number of suppliers, and ensure
that its fries tasted the same at every restaurant. McDonald's began switching
to frozen french fries in 1966 -- and few customers noticed the difference.
Nevertheless, the change had a profound effect on the nation's agriculture
and diet. A familiar food had been transformed into a highly processed
industrial commodity. McDonald's fries now come from huge manufacturing
plants that can peel, slice, cook, and freeze two million pounds of potatoes
a day. The rapid expansion of McDonald's and the popularity of its low-cost,
mass-produced fries changed the way Americans eat. In 1960 Americans consumed
an average of about eighty-one pounds of fresh potatoes and four pounds
of frozen french fries. In 2000 they consumed an average of about fifty
pounds of fresh potatoes and thirty pounds of frozen fries. Today McDonald's
is the largest buyer of potatoes in the United States.

The taste of McDonald's french fries played a crucial
role in the chain's success -- fries are much more profitable than hamburgers
-- and was long praised by customers, competitors, and even food critics.
James Beard loved McDonald's fries. Their distinctive taste does not stem
from the kind of potatoes that McDonald's buys, the technology that processes
them, or the restaurant equipment that fries them: other chains use Russet
Burbanks, buy their french fries from the same large processing companies,
and have similar fryers in their restaurant kitchens. The taste of a french
fry is largely determined by the cooking oil. For decades McDonald's cooked
its french fries in a mixture of about seven percent cottonseed oil and
93 percent beef tallow. The mixture gave the fries their unique flavor
-- and more saturated beef fat per ounce than a McDonald's hamburger.

In 1990, amid a barrage of criticism over the amount
of cholesterol in its fries, McDonald's switched to pure vegetable oil.
This presented the company with a challenge: how to make fries that subtly
taste like beef without cooking them in beef tallow. A look at the ingredients
in McDonald's french fries suggests how the problem was solved. Toward
the end of the list is a seemingly innocuous yet oddly mysterious phrase:
"natural flavor." That ingredient helps to explain not only why
the fries taste so good but also why most fast food -- indeed, most of
the food Americans eat today -- tastes the way it does.

Open your refrigerator, your freezer, your kitchen cupboards,
and look at the labels on your food. You'll find "natural flavor"
or "artificial flavor" in just about every list of ingredients.
The similarities between these two broad categories are far more significant
than the differences. Both are man-made additives that give most processed
food most of its taste. People usually buy a food item the first time because
of its packaging or appearance. Taste usually determines whether they buy
it again. About 90 percent of the money that Americans now spend on food
goes to buy processed food. The canning, freezing, and dehydrating techniques
used in processing destroy most of food's flavor -- and so a vast industry
has arisen in the United States to make processed food palatable. Without
this flavor industry today's fast food would not exist. The names of the
leading American fast-food chains and their best-selling menu items have
become embedded in our popular culture and famous worldwide. But few people
can name the companies that manufacture fast food's taste.

The flavor industry is highly secretive. Its leading
companies will not divulge the precise formulas of flavor compounds or
the identities of clients. The secrecy is deemed essential for protecting
the reputations of beloved brands. The fast-food chains, understandably,
would like the public to believe that the flavors of the food they sell
somehow originate in their restaurant kitchens, not in distant factories
run by other firms. A McDonald's french fry is one of countless foods whose
flavor is just a component in a complex manufacturing process. The look
and the taste of what we eat now are frequently deceiving -- by design.

The Flavor Corridor

HE New Jersey Turnpike runs through the heart of the
flavor industry, an industrial corridor dotted with refineries and chemical
plants. International Flavors & Fragrances (IFF), the world's largest
flavor company, has a manufacturing facility off Exit 8A in Dayton, New
Jersey; Givaudan, the world's second-largest flavor company, has a plant
in East Hanover. Haarmann & Reimer, the largest German flavor company,
has a plant in Teterboro, as does Takasago, the largest Japanese flavor
company. Flavor Dynamics has a plant in South Plainfield; Frutarom is in
North Bergen; Elan Chemical is in Newark. Dozens of companies manufacture
flavors in the corridor between Teaneck and South Brunswick. Altogether
the area produces about two thirds of the flavor additives sold in the
United States.

The IFF plant in Dayton is a huge pale-blue building
with a modern office complex attached to the front. It sits in an industrial
park, not far from a BASF plastics factory, a Jolly French Toast factory,
and a plant that manufactures Liz Claiborne cosmetics. Dozens of tractor-trailers
were parked at the IFF loading dock the afternoon I visited, and a thin
cloud of steam floated from a roof vent. Before entering the plant, I signed
a nondisclosure form, promising not to reveal the brand names of foods
that contain IFF flavors. The place reminded me of Willy Wonka's chocolate
factory. Wonderful smells drifted through the hallways, men and women in
neat white lab coats cheerfully went about their work, and hundreds of
little glass bottles sat on laboratory tables and shelves. The bottles
contained powerful but fragile flavor chemicals, shielded from light by
brown glass and round white caps shut tight. The long chemical names on
the little white labels were as mystifying to me as medieval Latin. These
odd-sounding things would be mixed and poured and turned into new substances,
like magic potions.

I was not invited into the manufacturing areas of the
IFF plant, where, it was thought, I might discover trade secrets. Instead
I toured various laboratories and pilot kitchens, where the flavors of
well-established brands are tested or adjusted, and where whole new flavors
are created. IFF's snack-and-savory lab is responsible for the flavors
of potato chips, corn chips, breads, crackers, breakfast cereals, and pet
food. The confectionery lab devises flavors for ice cream, cookies, candies,
toothpastes, mouthwashes, and antacids. Everywhere I looked, I saw famous,
widely advertised products sitting on laboratory desks and tables. The
beverage lab was full of brightly colored liquids in clear bottles. It
comes up with flavors for popular soft drinks, sports drinks, bottled teas,
and wine coolers, for all-natural juice drinks, organic soy drinks, beers,
and malt liquors. In one pilot kitchen I saw a dapper food technologist,
a middle-aged man with an elegant tie beneath his crisp lab coat, carefully
preparing a batch of cookies with white frosting and pink-and-white sprinkles.
In another pilot kitchen I saw a pizza oven, a grill, a milk-shake machine,
and a french fryer identical to those I'd seen at innumerable fast-food
restaurants.

In addition to being the world's largest flavor company,
IFF manufactures the smells of six of the ten best-selling fine perfumes
in the United States, including Estée Lauder's Beautiful, Clinique's
Happy, Lancôme's Trésor, and Calvin Klein's Eternity. It also
makes the smells of household products such as deodorant, dishwashing detergent,
bath soap, shampoo, furniture polish, and floor wax. All these aromas are
made through essentially the same process: the manipulation of volatile
chemicals. The basic science behind the scent of your shaving cream is
the same as that governing the flavor of your TV dinner.

"Natural" and "Artificial"

CIENTISTS now believe that human beings acquired the
sense of taste as a way to avoid being poisoned. Edible plants generally
taste sweet, harmful ones bitter. The taste buds on our tongues can detect
the presence of half a dozen or so basic tastes, including sweet, sour,
bitter, salty, astringent, and umami, a taste discovered by Japanese researchers
-- a rich and full sense of deliciousness triggered by amino acids in foods
such as meat, shellfish, mushrooms, potatoes, and seaweed. Taste buds offer
a limited means of detection, however, compared with the human olfactory
system, which can perceive thousands of different chemical aromas. Indeed,
"flavor" is primarily the smell of gases being released by the
chemicals you've just put in your mouth. The aroma of a food can be responsible
for as much as 90 percent of its taste.

The act of drinking, sucking, or chewing a substance
releases its volatile gases. They flow out of your mouth and up your nostrils,
or up the passageway in the back of your mouth, to a thin layer of nerve
cells called the olfactory epithelium, located at the base of your nose,
right between your eyes. Your brain combines the complex smell signals
from your olfactory epithelium with the simple taste signals from your
tongue, assigns a flavor to what's in your mouth, and decides if it's something
you want to eat.

A person's food preferences, like his or her personality,
are formed during the first few years of life, through a process of socialization.
Babies innately prefer sweet tastes and reject bitter ones; toddlers can
learn to enjoy hot and spicy food, bland health food, or fast food, depending
on what the people around them eat. The human sense of smell is still not
fully understood. It is greatly affected by psychological factors and expectations.
The mind focuses intently on some of the aromas that surround us and filters
out the overwhelming majority. People can grow accustomed to bad smells
or good smells; they stop noticing what once seemed overpowering. Aroma
and memory are somehow inextricably linked. A smell can suddenly evoke
a long-forgotten moment. The flavors of childhood foods seem to leave an
indelible mark, and adults often return to them, without always knowing
why. These "comfort foods" become a source of pleasure and reassurance
-- a fact that fast-food chains use to their advantage. Childhood memories
of Happy Meals, which come with french fries, can translate into frequent
adult visits to McDonald's. On average, Americans now eat about four servings
of french fries every week.

HE human craving for flavor has been a largely unacknowledged
and unexamined force in history. For millennia royal empires have been
built, unexplored lands traversed, and great religions and philosophies
forever changed by the spice trade. In 1492 Christopher Columbus set sail
to find seasoning. Today the influence of flavor in the world marketplace
is no less decisive. The rise and fall of corporate empires -- of soft-drink
companies, snack-food companies, and fast-food chains -- is often determined
by how their products taste.

The flavor industry emerged in the mid-nineteenth century,
as processed foods began to be manufactured on a large scale. Recognizing
the need for flavor additives, early food processors turned to perfume
companies that had long experience working with essential oils and volatile
aromas. The great perfume houses of England, France, and the Netherlands
produced many of the first flavor compounds. In the early part of the twentieth
century Germany took the technological lead in flavor production, owing
to its powerful chemical industry. Legend has it that a German scientist
discovered methyl anthranilate, one of the first artificial flavors, by
accident while mixing chemicals in his laboratory. Suddenly the lab was
filled with the sweet smell of grapes. Methyl anthranilate later became
the chief flavor compound in grape Kool-Aid. After World War II much of
the perfume industry shifted from Europe to the United States, settling
in New York City near the garment district and the fashion houses. The
flavor industry came with it, later moving to New Jersey for greater plant
capacity. Man-made flavor additives were used mostly in baked goods, candies,
and sodas until the 1950s, when sales of processed food began to soar.
The invention of gas chromatographs and mass spectrometers -- machines
capable of detecting volatile gases at low levels -- vastly increased the
number of flavors that could be synthesized. By the mid-1960s flavor companies
were churning out compounds to supply the taste of Pop Tarts, Bac-Os, Tab,
Tang, Filet-O-Fish sandwiches, and literally thousands of other new foods.

The American flavor industry now has annual revenues
of about $1.4 billion. Approximately 10,000 new processed-food products
are introduced every year in the United States. Almost all of them require
flavor additives. And about nine out of ten of these products fail. The
latest flavor innovations and corporate realignments are heralded in publications
such as Chemical Market Reporter, Food Chemical News, Food Engineering,
and Food Product Design. The progress of IFF has mirrored that of the flavor
industry as a whole. IFF was formed in 1958, through the merger of two
small companies. Its annual revenues have grown almost fifteenfold since
the early 1970s, and it currently has manufacturing facilities in twenty
countries.

Today's sophisticated spectrometers, gas chromatographs,
and headspace-vapor analyzers provide a detailed map of a food's flavor
components, detecting chemical aromas present in amounts as low as one
part per billion. The human nose, however, is even more sensitive. A nose
can detect aromas present in quantities of a few parts per trillion --
an amount equivalent to about 0.000000000003 percent. Complex aromas, such
as those of coffee and roasted meat, are composed of volatile gases from
nearly a thousand different chemicals. The smell of a strawberry arises
from the interaction of about 350 chemicals that are present in minute
amounts. The quality that people seek most of all in a food -- flavor --
is usually present in a quantity too infinitesimal to be measured in traditional
culinary terms such as ounces or teaspoons. The chemical that provides
the dominant flavor of bell pepper can be tasted in amounts as low as 0.02
parts per billion; one drop is sufficient to add flavor to five average-size
swimming pools. The flavor additive usually comes next to last in a processed
food's list of ingredients and often costs less than its packaging. Soft
drinks contain a larger proportion of flavor additives than most products.
The flavor in a twelve-ounce can of Coke costs about half a cent.

The color additives in processed foods are usually present
in even smaller amounts than the flavor compounds. Many of New Jersey's
flavor companies also manufacture these color additives, which are used
to make processed foods look fresh and appealing. Food coloring serves
many of the same decorative purposes as lipstick, eye shadow, mascara --
and is often made from the same pigments. Titanium dioxide, for example,
has proved to be an especially versatile mineral. It gives many processed
candies, frostings, and icings their bright white color; it is a common
ingredient in women's cosmetics; and it is the pigment used in many white
oil paints and house paints. At Burger King, Wendy's, and McDonald's coloring
agents have been added to many of the soft drinks, salad dressings, cookies,
condiments, chicken dishes, and sandwich buns.

Studies have found that the color of a food can greatly
affect how its taste is perceived. Brightly colored foods frequently seem
to taste better than bland-looking foods, even when the flavor compounds
are identical. Foods that somehow look off-color often seem to have off
tastes. For thousands of years human beings have relied on visual cues
to help determine what is edible. The color of fruit suggests whether it
is ripe, the color of meat whether it is rancid. Flavor researchers sometimes
use colored lights to modify the influence of visual cues during taste
tests. During one experiment in the early 1970s people were served an oddly
tinted meal of steak and french fries that appeared normal beneath colored
lights. Everyone thought the meal tasted fine until the lighting was changed.
Once it became apparent that the steak was actually blue and the fries
were green, some people became ill.

The federal Food and Drug Administration does not require
companies to disclose the ingredients of their color or flavor additives
so long as all the chemicals in them are considered by the agency to be
GRAS ("generally recognized as safe"). This enables companies
to maintain the secrecy of their formulas. It also hides the fact that
flavor compounds often contain more ingredients than the foods to which
they give taste. The phrase "artificial strawberry flavor" gives
little hint of the chemical wizardry and manufacturing skill that can make
a highly processed food taste like strawberries.

Although flavors usually arise from a mixture of many
different volatile chemicals, often a single compound supplies the dominant
aroma. Smelled alone, that chemical provides an unmistakable sense of the
food. Ethyl-2-methyl butyrate, for example, smells just like an apple.
Many of today's highly processed foods offer a blank palette: whatever
chemicals are added to them will give them specific tastes. Adding methyl-2-pyridyl
ketone makes something taste like popcorn. Adding ethyl-3-hydroxy butanoate
makes it taste like marshmallow. The possibilities are now almost limitless.
Without affecting appearance or nutritional value, processed foods could
be made with aroma chemicals such as hexanal (the smell of freshly cut
grass) or 3-methyl butanoic acid (the smell of body odor).

The 1960s were the heyday of artificial flavors in the
United States. The synthetic versions of flavor compounds were not subtle,
but they did not have to be, given the nature of most processed food. For
the past twenty years food processors have tried hard to use only "natural
flavors" in their products. According to the FDA, these must be derived
entirely from natural sources -- from herbs, spices, fruits, vegetables,
beef, chicken, yeast, bark, roots, and so forth. Consumers prefer to see
natural flavors on a label, out of a belief that they are more healthful.
Distinctions between artificial and natural flavors can be arbitrary and
somewhat absurd, based more on how the flavor has been made than on what
it actually contains.

"A natural flavor," says Terry Acree, a professor
of food science at Cornell University, "is a flavor that's been derived
with an out-of-date technology." Natural flavors and artificial flavors
sometimes contain exactly the same chemicals, produced through different
methods. Amyl acetate, for example, provides the dominant note of banana
flavor. When it is distilled from bananas with a solvent, amyl acetate
is a natural flavor. When it is produced by mixing vinegar with amyl alcohol
and adding sulfuric acid as a catalyst, amyl acetate is an artificial flavor.
Either way it smells and tastes the same. "Natural flavor" is
now listed among the ingredients of everything from Health Valley Blueberry
Granola Bars to Taco Bell Hot Taco Sauce.

A natural flavor is not necessarily more healthful or
purer than an artificial one. When almond flavor -- benzaldehyde -- is
derived from natural sources, such as peach and apricot pits, it contains
traces of hydrogen cyanide, a deadly poison. Benzaldehyde derived by mixing
oil of clove and amyl acetate does not contain any cyanide. Nevertheless,
it is legally considered an artificial flavor and sells at a much lower
price. Natural and artificial flavors are now manufactured at the same
chemical plants, places that few people would associate with Mother Nature.

A Trained Nose and a Poetic Sensibility

HE small and elite group of scientists who create most
of the flavor in most of the food now consumed in the United States are
called "flavorists." They draw on a number of disciplines in
their work: biology, psychology, physiology, and organic chemistry. A flavorist
is a chemist with a trained nose and a poetic sensibility. Flavors are
created by blending scores of different chemicals in tiny amounts -- a
process governed by scientific principles but demanding a fair amount of
art. In an age when delicate aromas and microwave ovens do not easily co-exist,
the job of the flavorist is to conjure illusions about processed food and,
in the words of one flavor company's literature, to ensure "consumer
likeability." The flavorists with whom I spoke were discreet, in keeping
with the dictates of their trade. They were also charming, cosmopolitan,
and ironic. They not only enjoyed fine wine but could identify the chemicals
that give each grape its unique aroma. One flavorist compared his work
to composing music. A well-made flavor compound will have a "top note"
that is often followed by a "dry-down" and a "leveling-off,"
with different chemicals responsible for each stage. The taste of a food
can be radically altered by minute changes in the flavoring combination.
"A little odor goes a long way," one flavorist told me. From
the archives:

"The Million-Dollar Nose," by William Langewiesche
(December 2000) Robert Parker Jr. is a plainspoken American with an astonishing
gift for judging wine. He is indefatigable and incorruptible, and his numerical
rating system is relied on by millions. His taste is changing the way wine
is made and sold. Naturally, the French hate him. Naturally, they honor
him. In order to give a processed food a taste that consumers will find
appealing, a flavorist must always consider the food's "mouthfeel"
-- the unique combination of textures and chemical interactions that affect
how the flavor is perceived. Mouthfeel can be adjusted through the use
of various fats, gums, starches, emulsifiers, and stabilizers. The aroma
chemicals in a food can be precisely analyzed, but the elements that make
up mouthfeel are much harder to measure. How does one quantify a pretzel's
hardness, a french fry's crispness? Food technologists are now conducting
basic research in rheology, the branch of physics that examines the flow
and deformation of materials. A number of companies sell sophisticated
devices that attempt to measure mouthfeel. The TA.XT2i Texture Analyzer,
produced by the Texture Technologies Corporation, of Scarsdale, New York,
performs calculations based on data derived from as many as 250 separate
probes. It is essentially a mechanical mouth. It gauges the most-important
rheological properties of a food -- bounce, creep, breaking point, density,
crunchiness, chewiness, gumminess, lumpiness, rubberiness, springiness,
slipperiness, smoothness, softness, wetness, juiciness, spreadability,
springback, and tackiness.

Some of the most important advances in flavor manufacturing
are now occurring in the field of biotechnology. Complex flavors are being
made using enzyme reactions, fermentation, and fungal and tissue cultures.
All the flavors created by these methods -- including the ones being synthesized
by fungi -- are considered natural flavors by the FDA. The new enzyme-based
processes are responsible for extremely true-to-life dairy flavors. One
company now offers not just butter flavor but also fresh creamy butter,
cheesy butter, milky butter, savory melted butter, and super-concentrated
butter flavor, in liquid or powder form. The development of new fermentation
techniques, along with new techniques for heating mixtures of sugar and
amino acids, have led to the creation of much more realistic meat flavors.

The McDonald's Corporation most likely drew on these
advances when it eliminated beef tallow from its french fries. The company
will not reveal the exact origin of the natural flavor added to its fries.
In response to inquiries from Vegetarian Journal, however, McDonald's did
acknowledge that its fries derive some of their characteristic flavor from
"an animal source." Beef is the probable source, although other
meats cannot be ruled out. In France, for example, fries are sometimes
cooked in duck fat or horse tallow.

Other popular fast foods derive their flavor from unexpected
ingredients. McDonald's Chicken McNuggets contain beef extracts, as does
Wendy's Grilled Chicken Sandwich. Burger King's BK Broiler Chicken Breast
Patty contains "natural smoke flavor." A firm called Red Arrow
Products specializes in smoke flavor, which is added to barbecue sauces,
snack foods, and processed meats. Red Arrow manufactures natural smoke
flavor by charring sawdust and capturing the aroma chemicals released into
the air. The smoke is captured in water and then bottled, so that other
companies can sell food that seems to have been cooked over a fire.

The Vegetarian Legal Action Network recently petitioned
the FDA to issue new labeling requirements for foods that contain natural
flavors. The group wants food processors to list the basic origins of their
flavors on their labels. At the moment vegetarians often have no way of
knowing whether a flavor additive contains beef, pork, poultry, or shellfish.
One of the most widely used color additives -- whose presence is often
hidden by the phrase "color added" -- violates a number of religious
dietary restrictions, may cause allergic reactions in susceptible people,
and comes from an unusual source. Cochineal extract (also known as carmine
or carminic acid) is made from the desiccated bodies of female Dactylopius
coccus Costa, a small insect harvested mainly in Peru and the Canary Islands.
The bug feeds on red cactus berries, and color from the berries accumulates
in the females and their unhatched larvae. The insects are collected, dried,
and ground into a pigment. It takes about 70,000 of them to produce a pound
of carmine, which is used to make processed foods look pink, red, or purple.
Dannon strawberry yogurt gets its color from carmine, and so do many frozen
fruit bars, candies, and fruit fillings, and Ocean Spray pink-grapefruit
juice drink.

N a meeting room at IFF, Brian Grainger let me sample
some of the company's flavors. It was an unusual taste test -- there was
no food to taste. Grainger is a senior flavorist at IFF, a soft-spoken
chemist with graying hair, an English accent, and a fondness for understatement.
He could easily be mistaken for a British diplomat or the owner of a West
End brasserie with two Michelin stars. Like many in the flavor industry,
he has an Old World, old-fashioned sensibility. When I suggested that IFF's
policy of secrecy and discretion was out of step with our mass-marketing,
brand-conscious, self-promoting age, and that the company should put its
own logo on the countless products that bear its flavors, instead of allowing
other companies to enjoy the consumer loyalty and affection inspired by
those flavors, Grainger politely disagreed, assuring me that such a thing
would never be done. In the absence of public credit or acclaim, the small
and secretive fraternity of flavor chemists praise one another's work.
By analyzing the flavor formula of a product, Grainger can often tell which
of his counterparts at a rival firm devised it. Whenever he walks down
a supermarket aisle, he takes a quiet pleasure in seeing the well-known
foods that contain his flavors.

Grainger had brought a dozen small glass bottles from
the lab. After he opened each bottle, I dipped a fragrance-testing filter
into it -- a long white strip of paper designed to absorb aroma chemicals
without producing off notes. Before placing each strip of paper in front
of my nose, I closed my eyes. Then I inhaled deeply, and one food after
another was conjured from the glass bottles. I smelled fresh cherries,
black olives, sautéed onions, and shrimp. Grainger's most remarkable
creation took me by surprise. After closing my eyes, I suddenly smelled
a grilled hamburger. The aroma was uncanny, almost miraculous -- as if
someone in the room were flipping burgers on a hot grill. But when I opened
my eyes, I saw just a narrow strip of white paper and a flavorist with
a grin.

Eric Schlosser is a correspondent for The Atlantic. His
article in this issue is adapted from his first book, Fast Food Nation,
to be published this month by Houghton Mifflin.